Whether it’s Niagara Falls on the U.S.-Canadian border or Yosemite Falls in Yosemite National Park, waterfalls are focal points which draw people to nature. Here in Great Smoky Mountains National Park, over 200,000 visitors a year traipse well worn trails to behold Grotto, Laurel, Abrams, Indian Creek, Rainbow, and other popular falls.
Why are waterfalls such magnets to humanity? Certainly the motion of water tumbling over rock is mesmerizing, as is the novelty of observing so much water closely and vividly. Yet perhaps author Harvey Broome was correct in stating that we see eternity in waterfalls—perpetual motion working independently of humankind, fueled by nothing more than gravity and rain.
Or, as researchers with less romantic views have proposed, waterfalls generate negative ions which make people feel good. Negative ions are negatively charged air molecules created by a number of natural and electronic processes, including ocean surf and waterfalls. Negative ion levels at large waterfalls are estimated to be 50 times higher than at other rural sites. Brighter moods, increased energy, improved physical performance, and better health are just some of the benefits that have been ascribed to exposure to high concentrations of negative ions.
Waterfalls also create a soothing “white noise,” a sound that engineers strive to imitate when they design sophisticated electronic gadgets intended to help humans relax, concentrate, or sleep. And on Southern summer afternoons, people delight in the cooling mist produced by waterfalls, a 100% natural, energy efficient form of evaporative air conditioning.
The Great Smoky Mountains abound with the two ingredients essential for waterfalls—water and an elevation gradient. In the Smokies high country, over 85" of rain falls on average each year. During wet years, peaks like Mt. Le Conte and Clingmans Dome receive over eight feet of rain.
Within Great Smoky Mountains National Park, elevations range from about 850' along Abrams Creek to 6,643' atop Clingmans Dome. Mt. Le Conte towers to 6,593' from a base of 1,292', making it the tallest (but not the highest), mountain in the East.
Besides water and topography, it’s geology that brings Smoky Mountain waterfalls into existence. Waterfalls generally occur at the interface of easily erodable and more resistant rock. In the Smokies, most waterfalls are underlain by ledges of a resistant rock called Thunderhead Sandstone. Over eons, the softer rock wears away downstream, creating the drop. Waterborne particles of dirt and sand cause most of the erosion. As long as the softer rock does not eventually yield to harder rock beneath it, the waterfall will continue to heighten each year.